Outputs (48)

Modelling the chemical enrichment of Population III supernovae: The origin of the metals in near-pristine gas clouds (2019)
Journal Article
Welsh, L., Cooke, R., & Fumagalli, M. (2019). Modelling the chemical enrichment of Population III supernovae: The origin of the metals in near-pristine gas clouds. Monthly Notices of the Royal Astronomical Society, 487(3), 3363-3376. https://doi.org/10.1093/mnras/stz1526

The most metal-poor, high redshift damped Lyman-α systems (DLAs) provide a window to study some of the first few generations of stars. In this paper, we present a novel model to investigate the chemical enrichment of the near-pristine DLA population.... Read More about Modelling the chemical enrichment of Population III supernovae: The origin of the metals in near-pristine gas clouds.

Fluorescent rings in star-free dark matter haloes (2019)
Journal Article
Sykes, C., Fumagalli, M., Cooke, R., Theuns, T., & Benítez–Llambay, A. (2019). Fluorescent rings in star-free dark matter haloes. Monthly Notices of the Royal Astronomical Society, 487(1), 609-621. https://doi.org/10.1093/mnras/stz1234

Photoheating of the gas in low-mass dark matter (DM) haloes prevents baryons from cooling, leaving the haloes free of stars. Gas in these ‘dark’ haloes remains exposed to the ultraviolet background (UVB), and so is expected to emit via fluorescent re... Read More about Fluorescent rings in star-free dark matter haloes.

Measurement of the primordial helium abundance from the intergalactic medium (2018)
Journal Article
Cooke, R., & Fumagalli, M. (2018). Measurement of the primordial helium abundance from the intergalactic medium. Nature Astronomy, 2(12), 957-961. https://doi.org/10.1038/s41550-018-0584-z

Almost every helium atom in the Universe was created just a few minutes after the Big Bang through a process commonly referred to as Big Bang nucleosynthesis1,2. The amount of helium that was made during Big Bang nucleosynthesis is determined by comb... Read More about Measurement of the primordial helium abundance from the intergalactic medium.

Searching for the lowest metallicity galaxies in the local universe (2018)
Journal Article
Hsyu, T., Cooke, R. J., Prochaska, J. X., & Bolte, M. (2018). Searching for the lowest metallicity galaxies in the local universe. Astrophysical Journal, 863(2), Article 134. https://doi.org/10.3847/1538-4357/aad18a

We report a method of identifying candidate low-metallicity blue compact dwarf galaxies (BCDs) from the Sloan Digital Sky Survey (SDSS) imaging data, and present 3 m Lick Observatory and 10 m W.M. Keck Observatory optical spectroscopic observations o... Read More about Searching for the lowest metallicity galaxies in the local universe.

One Percent Determination of the Primordial Deuterium Abundance (2018)
Journal Article
Cooke, R. J., Pettini, M., & Steidel, C. C. (2018). One Percent Determination of the Primordial Deuterium Abundance. Astrophysical Journal, 855(2), Article 102. https://doi.org/10.3847/1538-4357/aaab53

We report a reanalysis of a near-pristine absorption system, located at a redshift ${z}_{\mathrm{abs}}=2.52564$ toward the quasar Q1243+307, based on the combination of archival and new data obtained with the HIRES echelle spectrograph on the Keck te... Read More about One Percent Determination of the Primordial Deuterium Abundance.

Origins of carbon-enhanced metal-poor stars (2017)
Journal Article
Sharma, M., Theuns, T., Frenk, C. S., & Cooke, R. J. (2018). Origins of carbon-enhanced metal-poor stars. Monthly Notices of the Royal Astronomical Society, 473(1), 984-995. https://doi.org/10.1093/mnras/stx2392

We investigate the nature of carbon-enhanced metal-poor (CEMP) stars in Milky Way (MW) analogues selected from the EAGLE cosmological hydrodynamical simulation. The stellar evolution model in EAGLE includes the physics of enrichment by asymptotic gia... Read More about Origins of carbon-enhanced metal-poor stars.

The Little Cub: Discovery of an Extremely Metal-poor Star-forming Galaxy in the Local Universe (2017)
Journal Article
Hsyu, T., Cooke, R. J., Prochaska, J. X., & Bolte, M. (2017). The Little Cub: Discovery of an Extremely Metal-poor Star-forming Galaxy in the Local Universe. Astrophysical Journal, 845(2), Article L22. https://doi.org/10.3847/2041-8213/aa821f

We report the discovery of the Little Cub, an extremely metal-poor star-forming galaxy in the local universe, found in the constellation Ursa Major (a.k.a. the Great Bear). We first identified the Little Cub as a candidate metal-poor galaxy based on... Read More about The Little Cub: Discovery of an Extremely Metal-poor Star-forming Galaxy in the Local Universe.

Discovery of the most metal-poor damped Lyman-α system (2017)
Journal Article
Cooke, R. J., Pettini, M., & Steidel, C. C. (2017). Discovery of the most metal-poor damped Lyman-α system. Monthly Notices of the Royal Astronomical Society, 467(1), 802-811. https://doi.org/10.1093/mnras/stx037

We report the discovery and analysis of the most metal-poor damped Lyman α (DLA) system currently known, based on observations made with the Keck HIRES spectrograph. The metal paucity of this system has only permitted the determination of three eleme... Read More about Discovery of the most metal-poor damped Lyman-α system.

The primordial abundance of deuterium: ionization correction (2016)
Journal Article
Cooke, R., & Pettini, M. (2016). The primordial abundance of deuterium: ionization correction. Monthly Notices of the Royal Astronomical Society, 455(2), 1512-1521. https://doi.org/10.1093/mnras/stv2343

We determine the relative ionization of deuterium and hydrogen in low metallicity damped Lyman α (DLA) and sub-DLA systems using a detailed suite of photoionization simulations. We model metal-poor DLAs as clouds of gas in pressure equilibrium with a... Read More about The primordial abundance of deuterium: ionization correction.

The Primordial Deuterium Abundance of the Most Metal-poor Damped Lyman-alpha System (2016)
Journal Article
Cooke, R., Pettini, M., Nollett, K., & Jorgenson, R. (2016). The Primordial Deuterium Abundance of the Most Metal-poor Damped Lyman-alpha System. Astrophysical Journal, 830(2), Article 148. https://doi.org/10.3847/0004-637x/830/2/148

We report the discovery and analysis of the most metal-poor damped Lyman-alpha (DLA) system currently known, which also displays the Lyman series absorption lines of neutral deuterium. The average [O/H] abundance of this system is [O/H] = -2.804 +/-... Read More about The Primordial Deuterium Abundance of the Most Metal-poor Damped Lyman-alpha System.